President Donald Trump tweeted Saturday that 25 years of agreements with North Korea have failed, “making fools” of US negotiators.

In a pair of tweets sent Saturday afternoon, President Trump said that past agreements with North Korea have all been violated.

“Presidents and their administrations have been talking to North Korea for 25 years, agreements made and massive amounts of money paid … hasn’t worked, agreements violated before the ink was dry, makings fools of U.S. negotiators,” President Trump wrote. “Sorry, but only one thing will work!”

Asked by reporters later Saturday about the cryptic tweet, President Trump would only say: “You’ll figure that out pretty soon.”

Reached for comment on President Trump’s tweet, White House press secretary Sarah Sanders confirmed that all options are still on the table and that she had nothing further to add at this time.

This is not the first time the President has taken to the social media platform to challenge North Korea or its leader, Kim Jong Un, whom President Trump has nicknamed “rocket man” over Pyongyang’s continued development of nuclear weapons and ballistic missiles.

Responding to a UN speech by North Korea’s foreign minister in September, President Trump tweeted, “Just heard Foreign Minister of North Korea speak at U.N. If he echoes thoughts of Little Rocket Man, they won’t be around much longer!”

Saturday’s tweets came just two days after President Trump said the US will “do what we must do” to prevent further threats from North Korea.

“We cannot allow this dictatorship to threaten our nation or our allies with unimaginable loss of life,” he said at a meeting with top military officers.

“We will do what we must do to prevent that from happening, and it will be done if necessary, believe me.”

Those comments came less than a week after President Trump tweeted that Secretary of State Rex Tillerson was wasting his time in trying to open channels of negotiation with North Korea.

“Save your energy Rex, we’ll do what has to be done!” President Trump tweeted from his personal account on Sunday.

He followed up five hours later with another tweet, declaring, “Being nice to Rocket Man hasn’t worked in 25 years, why would it work now?” referring to North Korea’s Kim Jong Un, who inherited the mantle of leadership from his father in 2011.

President Trump said past White House administrations had been unsuccessful. “I won’t fail,” he declared.

North Korea, meanwhile, warned that Trump’s statements amounted to “extremely dangerous military gambling.”

“The U.S. strategic assets that were deployed on the Korean peninsula will be the first target of destruction by the revolutionary armed forces of [North Korea] which has the U.S. mainland across the Pacific within their striking range and the puppet forces will face total destruction,” the state-run Korean Central News Agency reported, citing a statement by an unnamed spokesman for the Pan-Korean Emergency Measure Committee for Opposing Nuclear War Drills against the North.

Tillerson had acknowledged on Saturday, after meetings in Beijing with Chinese leaders, that the Trump administration was keeping open direct channels of communications with North Korea and probing the North’s willingness to talk.

He provided no elaboration about those channels or the substance of any discussions. After he left China, his spokeswoman issued a statement saying that North Korean officials “have shown no indication that they are interested in or are ready for talks regarding denuclearization.”

“I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man … Save your energy Rex, we’ll do what has to be done!” ~ POTUS Trump